1. Field
The disclosed concept pertains generally to electrical switching apparatus and, more particularly, to circuit interrupters. The disclosed concept also pertains to receptacles.
2. Background Information
Known ground fault circuit interrupter (GFCI) and/or arc fault circuit interrupter (AFCI) receptacles include, for example, reverse feed and swapped wiring protection. However, if a single contact welds in the line path, then all of this protection is lost.
As shown in FIG. 1, some receptacles include three different electrical conductors 2,4,6. The first electrical conductor 2 includes a bendable/flexible contact arm 8 having a pair of contacts 10,12 capable of electrically connecting with the other two electrical conductors 4,6. This pair of contacts 10,12 makes and breaks electrical contact with two other contact arms 14,16, each having a single contact 18,20 to mate with one of the pair of contacts 10,12, respectively, of the bendable/flexible contact arm 8. The first electrical conductor 2 electrically connects to an electrical source (e.g., line) (not shown), the second electrical conductor 4 electrically connects to a load (e.g., a downstream receptacle) (not shown), and the third electrical conductor 6 electrically connects to an electrical connection (not shown) for attachment to a user load (e.g., one or two three-terminal female outlets (e.g., ports) on the face of the receptacle) (not shown). The pairs of contacts 10,18 and 12,20 can be opened and closed by conventional reset and test buttons (not shown) or by a trip mechanism (not shown) as are well known in the art. If any one contact pair of the two contact pairs 10,18 and 12,20 fails to open (e.g., welds), then two of the three electrical conductors 2,4,6 remain electrically connected together even in the tripped or open state of the receptacle. Hence, this presents a safety hazard upon the failure of one of the two contact pairs 10,18 and 12,20. For example, if such receptacle trips with a set of welded line contacts, then the line voltage is still present at the load terminals. Furthermore, if the line and load terminals (not shown) are electrically connected in error, then reverse feed detection does not function. Also, if such receptacle trips on a swapped line and neutral with a set of welded neutral contacts (not shown), then the line voltage is still present at the load terminals (not shown).
There is room for improvement in circuit interrupters.
There is also room for improvement in receptacles.